To find the angle whose sine is 0.42, we can use the inverse sine function, denoted as \(\sin^{-1}\) or \(\arcsin\).
Calculating the angle:
\[ \theta = \sin^{-1}(0.42) \]
Using a calculator to find the angle:
\[ \theta \approx 24.94^\circ \]
Now, rounding this to the nearest degree:
\[ \theta \approx 25^\circ \]
Therefore, the measure of the angle rounded to the nearest degree is
\[ \boxed{25} \]